Improvement in piston-valves for



, a part of this specitication, in which- UNITED STATES PATENT OFFICE.

THoMAs c. BALL, or nELLows FALLS, VERMONT, `Assioxon To mnsELF AND M. L. BAXTER.

IMPROVEMENT IN PlsToN-VALVES Foa STEAM-ENG|NET To all whom, it may concern.-

Specification forming part of Leiters Patent No. 41,035, dated December 22, 1363.

the head B. The valves may he packed 'on Be it known that I, THOMAS C. BALL, of; their peripheries so as to work statuut-ight Bellows Falls,in the countyot' Windham and State ot' Vermont, have invented certain new and uset'ul Improvements in Balanced Slidein the ches-t A hy metallic split rings in the usual manner; or they may be packed-vin any other suitable manner. 'Attached to the rod i Valves for 'bteain-llngines; and I do hereby D, outside ot` the pistou-.valves C C, are two declare that the following is a full, clear, and exact` description ot'the same, reference being had to the accompanying drawings, making Figure 1 represents alongitudinal vertical section of a valve-chest and elevation ot a valve constructed according to my invention. Fig. 2 is a similar view of a valve chest, showing the valves by dotted lines in the position f they occupy in relation to the ports when Q steam is cut ot't' at less than a full stroke of; the piston. Fig. 3 is a transverse section of g the steanichest in-the line Jv .rot Fig. 2. Fig. 4 isa front end view of the steam-chest.

`Similar letters ot' reference indicate correspending` parts in the several views.

also a means ot' lubricating the valves; and to this end the invention consists in having formed in the steam-chest, near each end thereof,separateixnlnotion and edncton steamf ports, which open into 'one another at thei` junction of thesteam-chest with the'steamcylinder, in combination with piston-valves,'l terior grooves c, which correspond in width which are balanced bythe pressure of a surrounding body of steam contained in grooves of corresponding width with the induction land eduction ports.

' The invention also consists iii providing the valve-rod with two extra pistons or heads,. whereby the eii'ect ot' the exhaust upon the piston-valves is counteracted.

The invention further consists incertain means provided for lubricating-.the valves,

- all as Will be hereinafter fully explained.

To enable others skilled in the art to which my invention appertains to understand the same, I will proceed lto describe it.

' In the accompanying drawings, A repre- `se'nts a stea-mchest, which is bored cylindrically through from end to end and fitted up with heads B B in the usual inanner. C C are two cylindrical or pistonwalves, adapted to work in the steam-chest, and secured to the rod D, which works through a stuffing-benzin other pistons or heads, E E, which are ot' considerable less width and of slightly less dialneter than the valves G (l, so that vthey work freely in the steam-chest.

In one side ofthe steam-chest, near each end, are two oblong ports, a. b, the former being the induction port or the opening through which steam passes into the cylinder, andthe latter the eduction port ortheo'peningthrough which the steam after use escapes from the cylinder into the steam-chest, whence it is conducted ott" into a condenser lor into theopcn air. as may be desired.

The ports -b at each end ol the steam-chest pass direct-ly through the same atright-angles y with the bore thereof, and the ports a pass ob- The object of this invention is to obtain in i liquely through and form-ajunction with the abalanced piston valve or valves a cut-off, and

port b neartheouter surface otthe steamchest, or where it unites with the steam-cylinder, making there one common port ot'equal length and ot'little less width than the two ports, a and b, combined. Opposite the inductior. and eduction ports c and b,V at each end ot' the steam-chest, there are formed around the inwith Athe ports a and b, and which are tilled with steam from the ports, so that the pistonvalves are balanced on all sides in passing the ports. Between the grooves c, above mentioned,at each end ol' thesteamchest, is formed a slight annular cavity, c, through which the lubricating material or compound contained in thecups dpasses to lubricate the piston valves C C. At no tiniein the working ofthe valves are the annular cavities c uncovered; consequently the oil has a free and unintersteain .contained inthe steam-chest.

A between the valves C O through a central opening, H, whence one of'thediagonal ports,

cylinder at one end, andafter moving the piston`(represented by red lines in Fig. 1) to the the straight or eduction port b into the space rupted How, and is not interfered with by theD The steam from the boiler enters the chesty af, being uncovered, itpasses i-ntothe steam.

opposite end of the cylinder it escapes through vionsly passed'rinto the steam-cylinder, and

to counteract v.the eieets which the exhauststeam wouldv otherwise 'have upon the valves,

' so as not'toere'ate a vacuum behind them in vmoving bctwcen'the piston-valve C and head E in the steam-chest, at .the sameend at which it prethence passes out of the steam-chest' through an ope'nngI,in`to a suitable condenser, or into the openair, as may be desired. v

When the engine is taking steam at either vend of the cylinder, a portion of the steam fills .the grooves .in the steamohest and forrn's'a nearly perfect balance ofthe valve. -The same e'ect is also producedi'n exhaust-steam. i The pistons'for heads E E a less degree by the are only designed and they are iitted'loosely in the steam-chest,

away from the ends of thesteamchest. i

The Valves may be worked by any suitable valve-gear, and the;` are s'o arranged incon- 'nection with the induction and edneti'on ports that vthey may be made to cut oj' steam at any desired point in the stroke of ,the steam-piston land leave the exhaust open at the opposite end of the cylinderuntil nearly the whole Y.strolie'is made or until .the steam-piston has traveled the entire length of the cylinder. Thesteam and exhaustorinduction and ednci formed ini the steam-chest," near `each end thereof,-i'n combination with the balanced piston-valves C C, IWhen arranged to operate in the manner described. A .Y

2. vIn combination with the balanced pistol valves C C and steam chest A,.closed at its ends, the pistons or heads E E, arranged to operate in the manner and for the purpose specified. K y

3. In combination with thebalanced pistonvalves C O, the annular cavities c, formed around the interior ofvthc steam-chest, in the nianner and for the purpose specified. l

Taos. c; BALn. Vitnesses:

M. L. BAXTER, F. W. KELLY, 

